Floating tong



L. V. DAVIDSON FLOATING TONG Nov. 10, 1964 3 Sheets-Sheet 1 Filed July 9, 1963 LUOIEN v. DAVIDSON INVENTOR. 9? J2 Nov. 10, 1964 L. v. DAVIDSON FLOATING TONG Filed July 9, 1965 3 Sheets Sheet 2 LUOIEN V. DAVIDSON INVENTOR.

ATTORNEYS United States Patent 3,156,495 FLOATING TONG Lucien V. Davidson, 1254 Columbia St, Port Angeies, Wash. Filed July 9, 19 63, Ser. No. 293,715 Claims. (Cl. 29-i-8$} This invention relates to log handling tongs and novel tong operating equipment as suspended for use from a boom. More specifically stated, the present invention pertains to the novel details of construction and the mode of operation of what I have herein designated to be floating, powered tongs, as especially adapted for the handling of logs, but equally adaptable for various analogous load moving operations.

It is the principal object of the invention to provide log or load handling tongs that are sustained in a cable suspended frame structure and wherein the tongs and the tong opening and closing mechanism has limited floating movement in the frame structure.

It is also an object of the invention to provide paired log handling tongs in association with a suspending frame structure in which an air cylinder is suspended and is operable to effect the opening and closing of the tongs for the engaging and pick up of a log or the like.

It is also an object of this invention to provide an arrangement of parts as above described wherein the tongs are caused to be closed under the weight of the air cylinder and the floating frame structure.

Further objects and advantages reside in the details of construction and combination of parts and in the mode of operation of the tongs as hereinafter described.

In accomplishing the above mentioned and other objects of the invention, I have provided the improved details of construction the preferred forms of which are illustrated in the accompanying drawings, wherein- FIG. 1 is an elevation of the present floating tongs, as shown in an unloaded normal, closed condition.

FIG. 2 is an enlarged longitudinal, sectional detail of one of the telescopic frame guides of the tong supporting plate.

FIG. 3 is a side elevation of the present tongs as shown in the normal condition of FIG. 1.

FIG. 4 is a horizontal section, taken on line 4-4 in FIG. 1.

FIG. 5 is a digrammatic showing of the closed tongs as suspended by a cable from a boom particularly showing the relative position of the telescopic guides for the floating structure.

FIG. 6 is similar view showing the guides and air cylinder when the tongs are fully opened.

FIG. 7 is a view showing the tongs of this invention as ordinarily used for log handling.

Referring more in detail to the drawings In its present preferred form of construction for log handling, the tong mechanism, as shown best in FIG. 1, comprises a main frame structure that is made up of two laterally spaced, coextensive, vertical side bars 10-10, joined across opposite faces of their upper end portions, by cross-plates 1111, and likewise across opposite faces of their lower end portions, by cross plates 1212, thus to provide a strong, rigid, rectangular frame structure of substantial length and relatively narrow width. For a better understanding of the usual size of this frame, it will here be noted that, as presently made, its overall length is approximately five feet and its over-all width is approximately twelve inches; these dimensions being desirable for its present use, but not critical and may be varied according to desires or requirements of use.

Mounted on the upper end portion of this frame structure, and extending in a horizontal plane thereacross and symmetrically to opposite sides thereof, as shown in FIG.

l, is a rectangular plate 13 which, at its opposite ends, has a pair of tubular 1414 fixed thereto and extended downwardly therefrom, parallel with and in the plane of the two frame bars 101(l; these tubular guides being open at their lower ends for a purpose presently disclosed.

Likewise, applied to and extending horizontally across the lower end portion of the main frame and equally beyond its opposite side edges, is a rectangular plate 15. The two plates, 13 and 15, are of substantially heavy and strong metal and are dimensioned to project symmetrically to the four sides of the main frame, as shown in FIGS. 1 and 2 and both plates are slotted as at 16 and 17, for an easy up and down sliding movement on the bars 1010 of the main frame in their floating action later explained.

Fixed vertically to the opposite end portions of the lower plate 15 as in FIG. 1, in axial alignment with the two laterally spaced, tubular guides 14-14 are guide rods I818 that are extended upwardly into and are adapted to move telescopically with the opening and closing action of the tongs as later explained, in the corresponding tubular guides 14-14, thus to serve to maintain the alignment and relationship of the relatively moving main parts of the unit as presently explained.

It has been shown best in FIG. 2 that paired tong suspending bars 19-49 are disposed lengthwise of and aiong opposite faces of the main structure and are welded to the corresponding opposite side edges of the floating plate 13, at 19' in FIGS. 1 and 3, depend therefrom slidingly through guiding slots or recesses 20-29 formed in opposite side edge portions of the lower floating plate 15, to terminate at a predetermined level below the horizontal lower end cross-plates 1212 of the main frame structure.

Between the lower ends of these two bars 1919, a pair of tongs T are disposed and are pivotally joined as in FIG. 3, for opening and closing action by a pivot bolt 21. This bolt is fixed in and is extended horizontally between the lower ends of the paired suspending bars 19-19. The two tong levers are shown in FIG. 1 as having relatively short upper end portions Ta extended upwardly beyond the pivot bolt 21, and relatively long lower end portions Tb below the pivot point that terminate in inturned log engaging points Tp.

The tongs T, as shown to be comprised by the paired complemental tong levers, preferably are of that well known type used quite generally in the logging industry.

At their upper ends, the two tong levers are connected by means of paired links 2727, with a clevis 28 that is pivotally attached by a bolt 29 to a lug 30 that is fixed to and depends from the medial portion of the lower end cross-plates 12-12 of the main frame structure. Each of the paired tong levers is provided on the outer edge of its lower portion Tb, with paired cars '31, and a pair of tong actuating links ZZZ-32 are pivotally attached at their lower and upper ends, respectively, to said ears 3131, and to cars 3333 depending from opposite end portions of plate 15, as has been shown in FIG. 1 and FIG. 2, thus to provide a means for effecting the opening and closing action of the tongs T incident to relative change in vertical spacing of plate 15 and the tong and pivot bolt 21, as supported between hanger bars The tong structure as a unit is suspended by a cable 46 that is attached to the upper end cross-plates 11-411 in the vertical axial line of the unit as indicated in FiG. 7. This cable is shown in PEG. 7 to be passed over and suspended from the outer end of a boom 42 that may be swung about the vertical axial line to a turn table support 43, as raised or lowered by the boom. Furthermore, the cable may be payed out and wound in over a sheave 44 at the outer end of the boom, from a cable winding drum 45 located conveniently adjacent the mounting end of the boom on the turn table structure 43.

Opening and closing of the tongs is effected by the following described means:

Located within the main frame structure, between the opposite side bars -40 and also between the horizon tal plates 13 and 15, in the axial line of the main frame, is a vertically disposed air cylinder 50 which is pivotally suspended by means as shown at 51, from the upper end late 13 of the floating frame. This cylinder contains a piston 52 from which a piston rod 53 extends downwardly and is connected pivotally at its lower end to the medial portion of plate 15, as at 54.

Air under pressure may be selectively admitted to the air cylinder 50 through a manually operable control valve 60 and hose connections 61-62, leading from the valve respectively to upper and lower ends of the cylinder 59, as in FIGS. 3 and 7, to effect the desired opening or closing actuation of the tongs.

With the understanding that the main frame structure is normally suspended in use by the cable 40, attached thereto at its upper end as disclosed, and that the pair of tongs T are connected to the medial portion of the lower cross-plates 12-12 by the clevis 23 and links 272'7 and that the pivot bolt 21 supporting the tongs between the hanger bars 1919 which are fixed at their upper ends to the oposite side edges of plate 13, it will also be reco nized that the combined weight of the tong opening linkage 3232, the plate and all other parts directly supported by plate 15, will normally operate to close the tongs together as shown in FIG. 1 and this will result in effecting that, closed relationship of the tongs and tong operating parts shown in FIG. 1.

If it is desired to open the tongs, air under pressure is admitted under control of valve through hose 62 to the lower end of cylinder 59. This results in the piston 52 moving upwardly in the cylinder as in FIG. 6, and the plate 15 being lifted accordingly to act through the paired links 32-32 to open the tongs. The open tongs may then be lowered over the log. Air under pressure is then delivered into the top end of the cylinder 5t through hose 61, to force the piston 52 downwardly and thus actuate plate 15 downwardly accordingly to act through links 32-32 to clamp the tongs on the log. Lifting of the log may then be effected by upwardly lifting of the main frame by cable and tong connections provided through links 27-27 and clevis 29 and lug 39. This lifting connection will be maintained by the tongs even though air is lost from the cylinder. This is by reason of the weight of the floating structure which is then sustained directly through the linkage 3232 as joined to the pivoted tongs, and is applied directly to hold the tongs closed on the log.

The log, as secured by the tongs, may then be lifted by an inwinding of the hoisting cable 49, and the log swung to unloading position by the swinging or other adjustments of the boom 42 as well known in the industry.

What I claim is:

1. A tong mechanism comprising a vertically suspended main frame, a pair of tongs with linkage at their upper ends suspending them from the lower end of said main frame, a floating frame structure mounted by and vertically movable on said main frame; said floating frame structure comprising independently movable upper and lower end plates, tong hanger bars fixed to said upper end plate and extended downwardly therefrom beyond the lower end of said main frame, and pivotally mounting said pair of tongs between them for opening and closing action, a power unit mounted between said upper and lower end plates of said floating frame structure and operable to effect change in the spacing of said end plates, and links joined with said pair of tongs and with said lower end plates of the floating frame to effect the opening and closing action of the tongs in accordance with the change in spacing of said end plates.

2. A tong mechanism comprising in combination; a hoisting cable, a main frame vertically suspended by said hoisting cable, a pair of load lifting tongs with links at their upper ends suspended from the lower end of said main frame for opening and closing action; a floating frame structure comprising an upper end plate and a lower end plate that are independently movable up and down on said main frame, a pair of hanger bars fixed at their upper ends to said upper plate with their lower ends disposed at opposite sides of said pair of tongs, a pivot shaft extended between the lower ends of said hanger bars and pivotally supporting said tongs thereon for their opening and closing action, and a power cylinder supported from said uper end plate, with a piston rod extended downwardly therefrom and connected to said lower end plate for effecting its movement toward or from the upper end plate and a pair of links pivotally joined at their upper and lower ends, respectively, to the lower end plate and to the paired tongs for actuating them between closed and open position with the change in spacing of said end plates of the floating frame.

3. A tong mechanism according to claim 2 wherein said main frame and said floating frame structure are associated in coaxial relationship and said upper and lower end plates of the floating frame are joined by telescopically assembled guiding members, symmetrically spaced from the vertical axial line of the mechanism.

4. The tong mechanism according to claim 2 wherein the main frame structure comprises parallel, spaced opposite side bars that are rigidly joined across upper and lower ends by end members, with said hoisting cable attached to the upper end member of the frame and said tong suspending links attached to the lower end member, and wherein said pair of tong hanger bars are attached at their upper ends to opposite side edges of the upper end plate of the floating frame, and have sliding movement through guide slots provided therefor in the lower end plate.

5. The tong mechanism of claim 4 wherein the parallel opposite side bars of said main frame pass slidably through guide slots in said upper and lower end plates of the floating frame, and the limit of up and down travel of the floating frame and the limit of up and down travel of the floating frame structure is established by the connecting upper and lower end members of the main frame.

References Cited in the file of this patent UNITED STATES PATENTS 2,217,629 Williams Oct. 8, 1940 2,776,164r Eckstein Jan. 1, 1957 

1. A TONG MECHANISM COMPRISING A VERTICALLY SUSPENDED MAIN FRAME, A PAIR OF TONGS WITH LINKAGE AT THEIR UPPER ENDS SUSPENDING THEM FROM THE LOWER END OF SAID MAIN FRAME, A FLOATING FRAME STRUCTURE MOUNTED BY AND VERTICALLY MOVABLE ON SAID MAIN FRAME; SAID FLOATING FRAME STRUCTURE COMPRISING INDEPENDENTLY MOVABLE UPPER AND LOWER END PLATES, TONG HANGER BARS FIXED TO SAID UPPER END PLATE AND EXTENDED DOWNWARDLY THEREFROM BEYOND THE LOWER END OF SAID MAIN FRAME, AND PIVOTALLY MOUNTING SAID PAIR OF TONGS BETWEEN THEM FOR OPENING AND CLOSING ACTION, A POWER UNIT MOUNTED BETWEEN SAID UPPER AND LOWER END PLATES OF SAID FLOATING FRAME STRUCTURE AND OPERABLE TO EFFECT CHANGE IN THE SPACING OF SAID END PLATES, AND LINKS JOINED WITH SAID PAIR OF TONGS AND WITH SAID LOWER END PLATES OF THE FLOATING FRAME TO EFFECT THE OPENING AND CLOSING ACTION OF THE TONGS IN ACCORDANCE WITH THE CHANGE IN SPACING OF SAID END PLATES. 